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Bidirectional Ultrafast Control of Charge Density Waves via Phase Competition
Honglie Ning1, Kyoung Hun Oh1, Yifan Su1
1Massachusetts Institute of Technology, Department of Physics, Cambridge, Massachusetts 02139, USA.
Physical Review Letters
|January 2, 2026
Summary
Researchers achieved ultrafast control over competing charge density waves (CDWs) in EuTe4 using light. The study reveals tunable phase manipulation, offering new pathways for controlling electronic states.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Ultrafast Phenomena
Background:
- Coexisting charge density waves (CDWs) exhibit complex interactions, offering potential for phase control via external stimuli.
- EuTe4 is a material hosting multiple CDW orders, making it a candidate for studying competitive CDW dynamics.
Purpose of the Study:
- To demonstrate and investigate the ultrafast optical control of coexisting charge density waves (CDWs) in EuTe4.
- To explore the influence of photoexcitation intensity on CDW amplitude dynamics and phase competition.
Main Methods:
- Time-resolved x-ray diffraction was employed to probe the dynamics of CDW orders with ultrafast temporal resolution.
- Phenomenological time-dependent Ginzburg-Landau theory simulations were used to model the observed phenomena.
Main Results:
- Optical excitation enables ultrafast manipulation of CDW amplitudes in EuTe4.
- Low excitation intensities favor enhancement of one CDW at the expense of another.
- High intensities induce a nonmonotonic temporal evolution of CDW amplitude, showing both increase and decrease.
- Tunable bidirectional control of CDW phase competition is achieved by varying photoexcitation intensity.
Conclusions:
- The study clarifies the interplay between coexisting CDWs in EuTe4, driven by optical quenching and phase competition.
- Ultrafast optical control over order parameters is demonstrated, highlighting the potential for manipulating electronic states in materials with competing orders.
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